Place rice in a saucepan, cover by 1cm with cold water, then heat over medium-high heat until just simmering (5 minutes). Stir, reduce heat to low, cover and cook until tender (10-15 minutes), then set aside.
Meanwhile, remove 12 outer cabbage leaves, blanch until tender (1-2 minutes), drain and set aside.
Cook whole cabbage heart in boiling water, removing and draining outer leaves as they become tender, then cook inner heart until tender (4-5 minutes) and drain well. Finely chop cooked cabbage and place in a large bowl.
Heat oil in a frying pan over high heat, add bacon, onion and garlic, stir occasionally until just cooked (5-10 minutes). Season to taste, add to chopped cabbage with sausage, rice, cheese, yolks and parsley, mix well, set aside.
Preheat oven to 180C. Form sausage mixture into six balls, wrap each ball in one blanched cabbage leaf, then use remaining outer leaves to completely cover mince and form a cabbage shape. Place in a casserole to fit snugly, scatter with thyme, dot with butter, pour wine over, cover and cook in oven, basting occasionally, until cabbage is very tender (2-2½ hours). Serve with crusty bread.